Article-working apparatus



May 23, 1950 B. A. RAETscH ARTICLE-WORKING APPARATUS Filed May 4, 1946lNvsNToR B. ARAETscH Patented May 23, 1950 UNITED STATES PATENT OFFICEARTICLE -WORKING APPARATUS Application May 4, 1946, Serial No. 667,345

Claims. (Cl. 242-9) This invention relates to article-working apparatus,and more particularly to means for starting windings of resistance Wiresaround supporting cards at lparticular points on the cards.

In the manufacture of potentiometer cards of a type including asupporting card having a predetermined prole and an extremely neresistance wire wound closely around the supporting card, it isdesirable to begin the Winding of the fine resistance wire around thepotentiometer card at a predetermined point thereon with respect to theprofile thereof. In the past, due to the extreme neness of the wire andthe close winding thereof, it has been diicult to start the winding at apredetermined point with respect to the proiile of the supporting card.

An object of the invention is to provide new and improvedarticle-working apparatus.

Another object of the invention is to provide new and improved apparatusfor Winding a iine insulating wire around a supporting card in apredetermined position with respect to the card.

In accordance with one embodiment of the invention, a supporting cardhaving a proiile and holes near the ends thereof in predeterminedpositions with respect to the profile is held securely by clamps and xedpins, which pins enter the holes in the supporting card in close fittingrelationship therewith. A serving head is mounted on a carriage which ismounted slidably on a lathe bed, and a feed screw serves to move theserving head along the supporting card to wind a resistance wire thereonwith a uniform lay. A dial indicator is mounted adjacent to the startingpoint of the serving head in a iiXed position with respect to thesupportingV card. A

spring-loaded plunger is mounted on the carriage in a position in whichit actuates the dial indicator when the serving head and the carriageare moved to a position near that at which the winding of a resistancewire is to be begun. When the serving head is in a position in which awinding of a resistance wire upon the supporting card is to be started,the dial indicator will have a Fig. 2 is a fragmentary, front elevationof the apparatus;

Fig. 3 is an enlarged, vertical section taken along line 3-3 of Fig. 2,and

Fig. 4 is an enlarged, top plan view ofv a portion of the apparatus.

Referring now in detail to the drawings, an apparatus for winding aresistance wire I0 (Fig. 1) having a very small diameter around asupporting card II to form a potentiometer card I2 is shown therein.This winding apparatus per se is disclosed and claimed in Patent No.2,382,451, issued October 14, 1945, and includes a serving head I5,which is mounted in a predetermined position on a carriage I6, which maybe moved along a lathe bed I'I by a feed screw I8. The winding apparatusalso includes clamps I9 and 2Il having fixed pins 2| and 22,respectively, which fit tightly within bores formed in the supportingcard II, of which a bore 23 is shown, to hold the card in a position inwhich a corner 25 and a lobe 26 of the card are positioned predetermineddistances from the pin 2|.

A high-sensitivity dial indicator 3D (Fig. 4) of a well-known type andhaving a spring-loaded plunger 3l, apointer 32 and a dial 33 calibratedin thousandths of an inch is mounted on a support 35 in a predeterminedposition with respect to the pin 2l, in which positionthe tip of thespring-loaded plunger 3| normally is a predetermined distance to theleft of the pin 2I, as viewed in Fig. 2, and the plunger 3| extendsparallel with the lathe bed. Y

A bracket 45 having arms 4I-4I having bores 42-42 (Fig. 3) formedtherein serves to mount an externally threaded guide 45 in the bores42-42. A knurled nut 46 fitting closelybut rotatably between the arms 4I-4I of the bracket 40 is threaded upon the guide 45. Knurlednuts 46 and41 threaded on the guide 45 hold the guide in a fixed position withrespect to the bracket 40. The nuts 46 and 41 may be threaded fartheronto or farther off of the guide 45 to adjust the position of the guidewith respect tothe bracket 46' and hence with respect to the servinghead I5. The guide 45 has a bore 50 formed therein and also is providedWith a counterbore 5I. A carriage plunger 52 is mounted slidably withinthe bores 50 and 5I and has a shoulder 55 formed thereon. A compressionspring 56 positioned in the counterbore 5I in the guide 45 urges theplunger 52 to the left, as viewed in Fig. 3, and the movement of theplunger 55 to the left is limited by a collar 51 fastened to the rightend of the plunger.

The bracket 40 is provided with holes GII-60,

in which a gauge rod 6I is slidably mounted. A pointer 62 inscribed onthe bracket indicates on a scale 63 formed on the gauge rod 6I thenormal position of the gauge rod with respect to the serving head I5. Anadjustable stop 65 mounted adjustably on an arm 66 formed on the guide45 is designed to engageY the endt oi. the gauge rod 6I to position theguide 45 with respect to the gauge rod and the bracket 4U. The stop 65is pinned to prevent adjustment thereof after it has been adjustedcorrectly initially..v When thestop 65 is in engagement with the gaugerod,

the position of the guide 45 withV respect tothe'Y serving head I5 maybe determined from thev reading of the pointer 62 on the scale 63 of thegauge rod. A locking pin B'I sslid'ably mounted in a bore formed in thebracket 40, and is designed to enter one of a plurality of bores 'II--TIformed in the gauge rod 6I to secure the gauge rod in one ci' severalpossible positionsthereof with respect to the bracket 40 and the servinghead I5.

The position of the pointer 62 with respect to the serving head I5 islknown, and the normal position of the tip of the plunger 3F of theinditions for different types of cards, and the nuts 46 and 4l areactuated to move theA guide to a position inwhich the stop 65 engagesthe gauge rod 6I. The distance1 from any mark on the gauge rod 6I totheright endf thereof also is known. Hence, for any particular setting ofthe gauge rod and guide ll,Y in which setting the stop 65 engages thegauge rod, the distance parallel to the lathe bed I'I from the left end:of the gauge rod to the serving head is known, and this distance remainsfixed until a;` further adjustment oi' the gauge rod and the guide 45-are made. Since the normali distance from the pin 2I to the tip of theplungerv 3I and the distance from the left end of' thegcarriage plunger512` toL the serving head I5 are known, the distance from the servinghead tothe pin 2| is'knovvn when the plunger 5 2 iust touches theplunger 3I. Hence, any further movement ofthe serving head I5 to theleft is indicated by the dial; indicator 30.

In the operation of the apparatus described hereinabove, the supportingcard II (Figs` l and 2) is thrust partially through the serving head I5,is placed over the pins 2| and 22' and is clamped by the clamps I9` and28 in a position in which the pins 2l and 22 project through the boresillustrated byv the bore 23, in close-tting engagement therewith so thatthe supporting card is heldl in a predetermined position with respect tothe dialV indicator TheV serving head I5 then is moved to the left, asviewed in Fig. 1, bythe. feed screw i8' and the carriage I6. As thecarriage approaches the position at which the winding of the resistanceWire i0 around the supporting card is to be started, the carriageplunger 52v engages the spring-loaded plunger 3I and urges it to theleft. The springv 56 is much stronger than the spring urging the plunger3I to. the right and' is normally under a, high enough compression thatthe carriage plunger 52" is not moved against the action` oi the spring5B until the spring urging the plunger 3|. to the right is completelycompressed'. 0n further movement, the spring 56 will be compressed toprevent damage to theindicator.

The movement of the spring-loaded plunger 3l to the left moves thepointer 32 from the zero point on the dial 33 in proportion to thelinear distance the plunger 3I is moved by carriage plunger 52, and whenthe pointer 32 is in a predetermined position with respect to the dial33, the serving head I5 is in the correct position with respect to thecorner 25 and the lobe 26 of the supporting card Il, the corner 25 andthe lobe 26 to begin Winding the iine resistance wire I0 upon thesupporting card. The indicator also indicates when. the serving head I5is winding particular turns of the resistance wire positioned near theinitial turn thereof on the card so that thev machine may be stopped andthese turns marked for future operations thereon.

rIhe dial indicator 3D is highly sensitive so that the position of theserving head I5 with respect to the supporting card II may be determinedWithin very close limits. Hence, the Winding of the resistance wire Iaround' thesupporting card Ii may be started at a very accuratelylocated position with respect to the corner' 25 and.' the lobe 26 of thesupporting card so that. potentiometer cards, illustrated by thepotentiometer card I2, may be made uniformly. The' carriage plunger 52is resiliently rather than rigidly mounted on the carriage I6 so thatdamage to the indicatorv from too great movement to the left' of thecarriage is prevented, but the spring 5t' islstrong enough andiscompressed enough initially that the indicator will' be` actuated toread its full range before the spring 56 will be further compressed.

What is claimed` is:

1. An apparatusv for Winding potentiometer cards, which comprises. alathe bed, means for clamping an insulating card atA the ends thereof ina predetermined position extending along the lathe bed, a serving headfor winding a wire around an insulating card held' by the card-holdingmeans, a carriage mounted onl the lathe bed forsupporting the servinghead1, a feed screw for reciprocating the carriage along the lathe bedto reciprocate theserving head' along the insulating card, aspring-loaded plunger carried by the carriage, and? a dial' indicatormounted in a predetermined position with respect to the insulating cardand engageable byv the springloaded plunger for indicating the positionof the serving head with respect. to-Y the insulating card.

2; An apparatus for winding potentiometer cards, which comprises aguideway, means for clamping an insulating card' at the ends thereof ina predetermined position extending along the guideway, a, serving headfor winding a wire aroundi an insulating card heldr by the cardhol'dingmeans, a carriage slidably mounted on theguideway for supporting theserving head, a feed' screwl for advancing the carriage along theguidewayV to advance the serving head along the insulating card,aspring-loaded plunger carried by the carriage, and a dial indicator atone end of the guideway in a predetermined position' with respect to theinsulating card and engageable by the spring-loadedv plunger forindieating the position ofthe` serving head with respect to theinsulating card when the carriage is moved to a position near that endof the guideway.

3. In a winding apparatus including a lathe bed, means for holding aninsulating card in a position extending alongA the lathe bed and in apredetermined relative longitudinal position with respect to the lathebed, a serving head, a carriage for mounting the serving head and a feedscrew for moving the carriage along the lathe bed to move the servinghead along an insulating card held by the card-holding means, means forindicating the starting position of the serving head with respect to theinsulating card comprising a spring-loaded plunger mounted on thecarriage and movable therewith along a predetermined path, and a dialindicator including a movable plunger positioned in said path inalignment with the rst-mentioned plunger and engageable thereby forindicating the position oi the serving head with respect to theinsulating card when the first-mentioned plunger engages the movableplunger of the indicator.

4. In a Winding apparatus including a guideway, means for holding aninsulating card in a predetermined position with respect to and parallelwith the guideway, a serving head for winding a ne resistance Wirearound an insu= lating card held by the card-holding means, a carriagemounted for movement along the guide- Way for holding the serving headand a feed screw for advancing the carriage along the guideway to movethe serving head along the insulating card, a device for indicating theposition oi the serving head with respect to the insulating cardcomprising a gauge including a pointer, a dial, and a movable plungerfor moving the pointer along the dial, said gauge being mounted in apredetermined position With respect to the insulating card, a bracketmounted on the carriage, a guide supported adjustably on the bracket, aspring-loaded plunger carried by the guide, and means for indicating thenormal position of the last-mentioned plunger with respect to thebracket, said last-mentioned plunger being mounted in a position inwhich it engages the rst-mentioned plunger near an end of the path oftravel of the carriage so that the pointer indicates on the dial theposition of the serving head with respect to the insulating card whenthe carriage is near that end of its path of travel.

5. An apparatus for Winding potentiometer cards, which comprises aguideway, means for clamping an insulating card in a predeterminedposition extending along the guideway, a serving head for winding a Wirearound an insulating card held by the card holding means, a carriageslidably mounted on the guideway for supporting the serving head, meansfor advancing the carriage along the guideway to advance the servinghead along the insulating card, an actuator carried by the carriage, anda dial indicator at one end of the guideway in a predetermined positionwith respect to the insulating card and engageable by the actuator forindicating the position of the serving head with respect to theinsulating card when the carriage is moved to a position near that endof the guideway.

BRUNO A. RAETSCH.

REFERENCES CITED rlhe following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 2,078,352 Summers Apr. 27, 19372,239,261 Turrettini Apr. 22, 1941 2,382,451 Stastney Aug. 14, 19452,389,859 Lambert Nov. 27, 1945 2,406,793 Benkoe Sept. 3, 1946 FOREIGNPATENTS Number Country Date 119,153 Germany Mar. 11, 1900

